The following is a passage from a private letter by Chesterton to an anti-Catholic who had written him, and found quoted in G.K. Chesterton: A Biography by Ian Ker (2011)
When you say that penitents pay for absolution, or that money can annul any marriage, it is merely as if you said that Margate is in Scotland, or that elephants lay eggs. It does not happen to be the fact, as you would discover if you investigated the facts. But when you suggest that there hangs on the fringe of the Catholic Church a vast horde of outcasts, criminals, prostitutes, etc- you refer to a real fact; and a very interesting and remarkable fact it is. They cannot get the Church's Sacraments or solid assurances, except by changing their whole way of life; but they do actually love the faith they cannot live by...which would be a fascinating psychological problem to anyone whose mind was free to consider it freely. If you explain it by supposing that the Church, though bound to refuse them Absolution where there is no Amendment, keeps in touch with them and treats their human dignity rather more sympathetically than does the world, Puritan or Pagan- that also probably refers to a real fact. It is one of the facts that convince me most strongly that Catholicism is what it claims to be. After two thousand years of compromises and concordats with every sort of social system, the Catholic Church has never yet become quite respectable. He still eats and drinks with publicans and sinners.